diff mbox

vhost_net: clear msg.control for non-zerocopy case during tx

Message ID 1370418046-11851-1-git-send-email-jasowang@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jason Wang June 5, 2013, 7:40 a.m. UTC 
When we decide not use zero-copy, msg.control should be set to NULL otherwise
macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs
wrongly.

Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
(vhost-net: skip head management if no outstanding).

This solves the following warnings:

WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
Call Trace:
[<ffffffff81796b73>] dump_stack+0x19/0x1e
[<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
[<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
[<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
[<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
[<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
[<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
[<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
[<ffffffff81061f46>] kthread+0xc6/0xd0
[<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
[<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
[<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/vhost/net.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

Comments

Michael S. Tsirkin June 5, 2013, 9:02 a.m. UTC | #1 
On Wed, Jun 05, 2013 at 03:40:46PM +0800, Jason Wang wrote:
> When we decide not use zero-copy, msg.control should be set to NULL otherwise
> macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs
> wrongly.
> 
> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
> (vhost-net: skip head management if no outstanding).
> 
> This solves the following warnings:
> 
> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
> Call Trace:
> [<ffffffff81796b73>] dump_stack+0x19/0x1e
> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
> [<ffffffff81061f46>] kthread+0xc6/0xd0
> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Good catch.

Acked-by: Michael S. Tsirkin <mst@redhat.com>

This needs to go into stable as well.

> ---
>  drivers/vhost/net.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 2b51e23..b07d96b 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -436,7 +436,8 @@ static void handle_tx(struct vhost_net *net)
>  				kref_get(&ubufs->kref);
>  			}
>  			nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
> -		}
> +		} else
> +			msg.msg_control = NULL;
>  		/* TODO: Check specific error and bomb out unless ENOBUFS? */
>  		err = sock->ops->sendmsg(NULL, sock, &msg, len);
>  		if (unlikely(err < 0)) {
> -- 
> 1.7.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sergei Shtylyov June 5, 2013, 1:44 p.m. UTC | #2 
Hello.

On 05-06-2013 11:40, Jason Wang wrote:

> When we decide not use zero-copy, msg.control should be set to NULL otherwise
> macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs
> wrongly.

> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
> (vhost-net: skip head management if no outstanding).

> This solves the following warnings:

> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
> Call Trace:
> [<ffffffff81796b73>] dump_stack+0x19/0x1e
> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
> [<ffffffff81061f46>] kthread+0xc6/0xd0
> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70

> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>   drivers/vhost/net.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)

> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
> index 2b51e23..b07d96b 100644
> --- a/drivers/vhost/net.c
> +++ b/drivers/vhost/net.c
> @@ -436,7 +436,8 @@ static void handle_tx(struct vhost_net *net)
>   				kref_get(&ubufs->kref);
>   			}
>   			nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
> -		}
> +		} else

    You have to use {} on the *else* branch if you have it of the *if* 
branch (and vice versa), according to Documentation/CodingStyle.

> +			msg.msg_control = NULL;

WBR, Sergei

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Jason Wang June 6, 2013, 3:27 a.m. UTC | #3 
On 06/05/2013 09:44 PM, Sergei Shtylyov wrote:
> Hello.
>
> On 05-06-2013 11:40, Jason Wang wrote:
>
>> When we decide not use zero-copy, msg.control should be set to NULL
>> otherwise
>> macvtap/tap may set zerocopy callbacks which may decrease the kref of
>> ubufs
>> wrongly.
>
>> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
>> (vhost-net: skip head management if no outstanding).
>
>> This solves the following warnings:
>
>> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
>> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge
>> stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
>> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
>> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
>> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
>> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
>> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
>> Call Trace:
>> [<ffffffff81796b73>] dump_stack+0x19/0x1e
>> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
>> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
>> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
>> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
>> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>> [<ffffffff81061f46>] kthread+0xc6/0xd0
>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>>   drivers/vhost/net.c |    3 ++-
>>   1 files changed, 2 insertions(+), 1 deletions(-)
>
>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>> index 2b51e23..b07d96b 100644
>> --- a/drivers/vhost/net.c
>> +++ b/drivers/vhost/net.c
>> @@ -436,7 +436,8 @@ static void handle_tx(struct vhost_net *net)
>>                   kref_get(&ubufs->kref);
>>               }
>>               nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
>> -        }
>> +        } else
>
>    You have to use {} on the *else* branch if you have it of the *if*
> branch (and vice versa), according to Documentation/CodingStyle.

checkpatch.pl didn't complain this, will send v2.

Thanks
>
>> +            msg.msg_control = NULL;
>
> WBR, Sergei
>
> -- 
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Sergei Shtylyov June 6, 2013, 5:12 p.m. UTC | #4 
Hello.

On 06/06/2013 07:27 AM, Jason Wang wrote:

>>> When we decide not use zero-copy, msg.control should be set to NULL
>>> otherwise
>>> macvtap/tap may set zerocopy callbacks which may decrease the kref of
>>> ubufs
>>> wrongly.
>>> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
>>> (vhost-net: skip head management if no outstanding).
>>> This solves the following warnings:
>>> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
>>> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge
>>> stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
>>> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
>>> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
>>> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
>>> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
>>> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
>>> Call Trace:
>>> [<ffffffff81796b73>] dump_stack+0x19/0x1e
>>> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
>>> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
>>> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
>>> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
>>> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
>>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>>> [<ffffffff81061f46>] kthread+0xc6/0xd0
>>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>>> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
>>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>>> ---
>>>    drivers/vhost/net.c |    3 ++-
>>>    1 files changed, 2 insertions(+), 1 deletions(-)
>>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>>> index 2b51e23..b07d96b 100644
>>> --- a/drivers/vhost/net.c
>>> +++ b/drivers/vhost/net.c
>>> @@ -436,7 +436,8 @@ static void handle_tx(struct vhost_net *net)
>>>                    kref_get(&ubufs->kref);
>>>                }
>>>                nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
>>> -        }
>>> +        } else
>>     You have to use {} on the *else* branch if you have it of the *if*
>> branch (and vice versa), according to Documentation/CodingStyle.
> checkpatch.pl didn't complain this, will send v2.

     Yes, this check is what it seems to lack still.

> Thanks
>

WBR, Sergei

--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
David Miller June 10, 2013, 9:32 p.m. UTC | #5 
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Wed, 5 Jun 2013 12:02:52 +0300

> On Wed, Jun 05, 2013 at 03:40:46PM +0800, Jason Wang wrote:
>> When we decide not use zero-copy, msg.control should be set to NULL otherwise
>> macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs
>> wrongly.
>> 
>> Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84
>> (vhost-net: skip head management if no outstanding).
>> 
>> This solves the following warnings:
>> 
>> WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]()
>> Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun]
>> CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566
>> Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011
>> ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48
>> ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0
>> ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58
>> Call Trace:
>> [<ffffffff81796b73>] dump_stack+0x19/0x1e
>> [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0
>> [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20
>> [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net]
>> [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net]
>> [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net]
>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>> [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net]
>> [<ffffffff81061f46>] kthread+0xc6/0xd0
>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>> [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0
>> [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
>> 
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> 
> Good catch.
> 
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> 
> This needs to go into stable as well.

Applied and queued up for -stable.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 2b51e23..b07d96b 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -436,7 +436,8 @@  static void handle_tx(struct vhost_net *net)
 				kref_get(&ubufs->kref);
 			}
 			nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV;
-		}
+		} else
+			msg.msg_control = NULL;
 		/* TODO: Check specific error and bomb out unless ENOBUFS? */
 		err = sock->ops->sendmsg(NULL, sock, &msg, len);
 		if (unlikely(err < 0)) {